How to choose your MTB disc brakes?
The disc brakes have been very present in the moutnain bike world in recent years: they have succeeded in imposing themselves and are now considered a standard.
It's also interesting to note that the very high-end road bikes are beginning to use hydraulic brakes.
Their success is due to several factors: their efficiency, reliability and viability.
As the number of different products offered is important, Alltricks offers you this detailed buying guide!
There are two types of disc brakes: mechanical and hydraulic.
Mechanical disc brakes make up the most of the entry-level range, they are less powerful, less precise and require more maintenance. When the pilot brakes, he/she pulls a cable that will force two pads to come into contact with the disc, which will cause the bike to slow down.
The hydraulic disc brakes are a single unit, the oil contained in the duct mustn't escape from the lever to the pistons. They're therefore not exposed to external elements. When the pilot brakes, the movement of the lever will push the oil into the casing which will itself exert pressure on the pistons that will push the pads against the disc. Only then will the bike slow down.
Different braking powers
Several variables will modify the braking power
The size of the discs
The diameters of the discs range from 140mm to 203mm. The larger the diameter, the more powerful the brake.
The number of pistons
There are two, four, or six of them. The pistons are the elements that will push the pads to come into contact with the disc. The more numerous they are, the more powerful the brakes will be.
The type of pads used:
- The metal pads will be more powerful on big braking (DH or Freeride types).
- Organic pads (mainly composed of resin) will be very effective for punctual braking at moderate speed.
- Semi-metal pads will offer a fairly interesting compromise between metallic and organic pads.
Recently, ventilated pades have also become available. They can be used to lower the disc temperature in order to optimise braking efficiency.
Depending on how you use your bike, it's important to consider these latter elements: the more the brakes are used, the more important the size of the disc used and the number of pistons must be within the braking system.
Different types of discs and calipers
Two disc standards
Before purchasing disc brakes, it's important to check the compatibility of its hubs. The latter must have been designed to accommodate a disc.
Depending on the technologies, Shimano has "centerlock" discs, or discs screwed with 6 holes by other manufacturers.
The fork, or frame, must also be compatible with the brake caliper installation. There are two standards: IS and PM.
For the IS standard, the screws that connect the caliper to the bicycle are perpendicular to the caliper. On the contrary, for the PM standard, the screws are parallel to the caliper. Many adapters are used to widen bracket compatibility with the brake calipers. It's thus possible to change from a standard IS frame/fork to a standard PM caliper.
Each fork or frame support is provided for a defined disc size; if the latter is not the same as the discs you own, it will be necessary to purchase an adapter.
You can consult our guide , to know what type of standard you have, and what type of adapter to use.